Convert.ToUInt64 (String) converts string to 64-bit unsigned integer.
Class Sample Public Shared Sub Main() Dim values() As String = { "One", "1.34e28", "-18", "-6.00", " 0", "137", Int32.MaxValue.ToString() } Dim result As ULong For Each value As String In values Try result = Convert.ToUInt64(value) Console.WriteLine(result) Catch e As Exception Console.WriteLine("Exception") End Try Next End Sub End Class